If two triangles on the horizontal side divide the side into three equal parts.

S 1:S2 = 8:6 = 4 :3

(S 1-S2):S2 = 1:3

Large S2/3 = (10/3) * 6/(3 * 2) =10/3 (square centimeter)

If it's a triangle,

The edge of S 1 is 8, the edge of S2 is 6/√ 3 = 2 √ 3, and the sum of S 1 and the edge of S2 is 8+2√3 > 10, which is inconsistent with the drawing.